1. Field of the Invention
The present invention relates to an information display apparatus for displaying the results of information retrieval or analysis of input information, and more specifically to an information comparison display apparatus using colors and a method thereof, in which a color is assigned to each piece of character-string information according to the results of comparison of the pieces of character-string information. Each piece of character-string information is outputted together with the assigned color so as to clearly visualize the results of the comparison.
2. Description of the Related Art
In general, the method of determining a presentation unit in accordance with the structure of target information becomes important when pieces of input information are compared and the difference between the pieces of input information is displayed. For example, in cases where the structure and meaning of input information is specified in advance, such as a case of a software program, it is necessary to reflect the structure and meaning of the information in comparison results represented by a display object so as to allow a user to easily understand the comparison results. Thus, instead of simply displaying the difference between the pieces of input information, consideration must be given to the method of determining a presentation unit of the comparison results.
However, in the case of the comparison of pieces of character-string information, to which the present invention is mainly directed, a unit having a definite form, such as a piece of text or a word, becomes a presentation unit of a comparison result. Generally, the following three conventional methods are used for displaying the results of information retrieval or analysis of information, and for displaying the comparison of the results: a first method, in which results are displayed and a user compares the displayed results; a second method, in which a characteristic part of results are extracted and presented to a user; and a third method, in which a mark is put on a different part or common part of results and only the marked part is displayed.
FIGS. 1-3 show an example of the comparison of pieces of character-string information using the conventional method. FIGS. 1 and 2 show the relationship between systems of 1995 and those of 1999, respectively. The diagrams as shown in FIGS. 1 and 2 are formed with elements enclosed in a box, which indicate character-string information, and lines indicating the relationship between the elements. These diagrams correspond to the above-mentioned first method. Comparison between FIGS. 1 and 2 allows a user to make a comparison between the systems of 1995 and 1999.
FIG. 3 corresponds to the above-mentioned second method. A part common to FIGS. 2 and 3 is extracted and displayed in FIG. 3. FIG. 3 allows a user to understand the difference between two pieces of input information.
Thus, in the conventional methods, a user can only understand the difference between pieces of input information and a common part of the pieces of input information, thus the viewpoint or aim of the display of results remains unclear. Therefore, the results cannot always be understood easily, and furthermore, there is a possibility that an omission occurs. In cases where three or more pieces of input information are compared, it is difficult to understand the results of comparison between two of the pieces of input information.
That is, simply displaying the difference between pieces of input information only allows a user to partly understand the input information, and does not allow the user to fully understand the input information. It is necessary to clarify the characteristic of each part of input information in relation to the entire input information to make the user to fully understand the input information. For example, in a retrieval system, output results are ranked and displayed according to the frequency of occurrence of a keyword. However, if comparison results regarding only part of input information are presented to a user, the user cannot obtain overall ranking information.
For example, if a mark is put on an element of input information so as to make a distinction between elements, the characteristic of compared parts of the input information can only be seen from a single point of view. The use of different marks indicating a plurality of viewpoints is likely to result in the user misunderstanding or misinterpreting the information. In general, the results of information retrieval are displayed by marking a retrieval keyword. However, a mark cannot be effectively used for graphically displaying the relationship between retrieval results or for comparing the retrieval results.
FIG. 4 shows another example of the graphical visualization of the comparison results of character-string information, based on the conventional method. Three words displayed in the search term priorities section in the lower left corner of the screen image as shown in FIG. 4, are used as keywords in retrieval. The three keywords are displayed in the center of the right side of the screen image, and words relevant to the keywords are displayed around the keywords. A user can create a new retrieval condition by selecting a new keyword from among the displayed words relevant to the keywords.
In some cases, colors are used for displaying the comparison results of character-string information, so as to visually emphasize or highlight the comparison results. However, there is no example of using colors for indicating the results of comparison or the difference between pieces of information. For example, in a retrieval system, colors are used so that a user can easily understand the position where a retrieval key appears, but are not used for making the user understand differences or changes. In some cases of graphical representation, nodes of different forms are used for indicating the difference in quantity. However, such conventional graphical representation does not use colors for indicating the comparison or difference between pieces of information.
As described above, in the case of comparison between pieces of character-string information, a piece of text or word is used as a presentation unit of comparison results. However, extracting only a characteristic part or displaying elements which are simply arranged is not sufficient to make a user understand comparison results well, resulting in that the user cannot easily understand the difference between pieces of information. In the case of inputting a series of character-string information, such as time-series information, it is desirable to indicate a series of changes in displaying comparison results. However, it is difficult to display such a series of changes in a manner in which a user can easily understand the series of changes.
Although the technique for representing a relationship by means of a graph and the technique for using colors only as marks already exist, there is no technique for using colors for indicating the results of comparison or difference between pieces of character-string information. Thus, the conventional method has the problem that the results of comparison or difference between pieces of input information cannot be easily understood.